A/B Loop
A/B Loop lets you mark two points in the timeline and repeat the section between them continuously. All protocol outputs loop in sync with the audio — no separate configuration is needed on receiving devices.
Setting loop points
- Set Loop A (start) — press
[or click the A button in the transport while the playhead is at the desired start position - Set Loop B (end) — press
]or click the B button while the playhead is at the desired end position - Both at once — right-drag across the music waveform to set A and B in one move; the drag replaces any loop that was already set
You can set A and B while the transport is playing or stopped. Setting A while playing marks the current playback position. Setting B while playing marks the position at the moment you press the key.
[ and ] only set the loop points; they do not jump between cues. To jump to the previous or next cue, use J and K.
A must come before B. If you set a point that would break that order — for example A at or after B — LTCast shows a message and keeps the previous point, so move or clear the other point first.
Active looping
Once both A and B are set, the transport loops. Behavior during looping:
- Playback reaches the B point and jumps back to the A point. The jump restarts the audio at A, so a very short gap in the music and LTC is possible — rehearse the loop before you rely on it live
- LTC audio restarts at the A timecode address on each loop cycle
- MTC carries on with the timecode of the A position; no separate Full Frame locate message is sent at the loop point
- Art-Net and OSC follow the timecode back to the A position on each loop
- The loop region is shown as a highlighted band on the waveform, with dashed A and B lines
Clearing the loop
- Click the ✕ (Clear Loop) button beside the A and B buttons — it appears once both points are set and removes both
- Click the A or B button again to remove just that point; with one point missing there is no loop
- Load another song — loop points are cleared whenever the song changes
[ and ] never clear anything: pressing one again just moves that point to the current position. Esc stops playback but leaves the loop points in place. After clearing, playback continues from the current position without looping.
Loop points and songs
Loop points belong to the song that is loaded. When the song changes — you load another song, or auto-advance moves on — they are cleared, so set them again for each song. The whole-song Loop button next to A and B is separate: it repeats the entire song.